Strand cooling support system

ABSTRACT

The invention comprises a set of four interconnected housing units which face the four sides of a rectangular continuous cast strand. Enclosed within each housing unit is a set of guide plates which may be moved toward the cast strand surface, but not in direct contact therewith. The plates contact and restrain the surface of the strand whenever it tends to bulge and break out due to excessive internal metallostatic pressure.

United States Patent n 1 Toperzer et a].

I451 Sept. 11,1973

[ STRAND COOLING SUPPORT SYSTEM [75] Inventors: John W. Toperzer; Dale K. Beachy,

both of Pittsburgh, Pa.

"[73] Assig'iiee'i' li'o'pfier sfioiiipaiiiinc, PittsBurgh,

22 Filed: Apr. 28, 1972 21 Appl. No.: 248,399

[51] Int. Cl B22d 11/12 [58] Field of Search 164/82, 89, 273 R, 164/282, 283

[56] References Cited UNITED STATES PATENTS 3,375,864 4/1968 Butkevich et 31...; 164/283 x UTSTGQIIQIQQ."III..." "l: .'.'..T.'...1 $4 23i 3,463,220 8/1969 Moritiz .i l64/89 X 3,515,202 6/1970 Bick et al 3,620,285 ll/l97l Olsson 164/282 X Primary Examiner-R. Spencer Annear AttorneySherman H. Barber et al.

[57] ABSTRACT The invention comprises a set of four interconnected housing units which face the four sides of a rectangular continuous cast strand. Enclosed within each housing unit is a set of guide plates which may be moved toward the cast strand surface, but not in direct contact therewith. The plates contact and restrain the surface of the strand whenever it tends to bulge and break out due to excessive internal metallostatic pressure.

10 Claims, 3 Drawing Figures PAIENIEUSEPIHQN 3'75? 849 SHEET 1 OF 3 PATENTEnsm ima snmaor'a 1 STRAND COOLING SUPPORT SYSTEM BACKGROUND OF THE INVENTION In continuous casting of steel and other metals, initial solidification of the metal takes place in a water-cooled mold. The cast strand that emerges from the mold has an outer shell or skin that is relatively thin, and the shell thickness depends upon the temperature, speed, size of the strand, and kind of metal being cast. If any one or more of these factors is adversely varied to any appreciable degree, the shell thickness is so thin that it can not sustain the internal metallostatic pressure and it ruptures in a breakout. Breakouts usually occur just below the mold.

Present practice is to install a combination of foot rolls that are mounted to the bottom of the mold and that press against the strand shell, and water sprays that jet cooling water onto the strand surface to cool the surface so that it has enough strength to resist theinternal metallostatic pressure.

Because of the ever present danger of breakouts in the zone just below the mold, it is important that any equipment installed in this zone be reliable, easy to maintain, and readily adjustable under varying conditions. How the apparatus of the present invention accomplishes these objectives and others will be readily apparent to those skilled in the art from the following description of the embodiment of the invention.

. BRIEF SUMMARY OF THE INVENTION In a continuous casting apparatus, including a mold from which a cast strand is continuously withdrawn, a strand cooling support system includes a plurlity of chambers and each chamber has one open side disposed adjacent a surface of the cast strand. Within each chamber there are a plurality of spaced apart guide plates that are unitized by a connecting plate to which is attached a tubular member containing a resilient device and a plunger coacting therewith of a screw extending outside of each chamber for adjusting the force exerted by the resilient device on the unitized structure. A spray is located in each chamber for ejecting cooling fluid onto the surface of the strand and means is provided for pressurizing the interior of each chamber.

For a further understanding of the invention and for features and advantages thereof, reference may be made to the following description and the drawing which illustrates a preferred embodiment of equipment in accordance with the invention.

BRIEF DESCRIPTION OF THE DRAWINGS 1 In the drawings: 7

FIG. I is a schematic exploded perspective view, partly cut away, of one embodiment of the invention;

FIG. 2 is a sectional plan view' of one portion of the embodiment of the invention shown in FIG. 1; and

FIG. 3 is a sectional view along line III-III of FIG. 2.

DETAILED DESCRIPTION Referring to FIG. 1, a billet cooling support system 11 in accordance with the present invention includes four interconnected housing units 13, 15, 17, 19. Each housing unit 13, 15, 17, 19 is pivotally connected at two hinged corners 21, 23 each to two adjacent housing units disposed at right angles to the one housing unit, as is shown in FIG. 3. Each hinge 21 and 23 is assemshown in FIG. 1). The hinge pin 25, it will be noted, is threaded at the vertical end and it cooperates with a threaded hole 27 in a base plate 29 affixed to or forming a part of the continuous casting mold.

Each housing unit 13, 15, 17, 19 also has two lugs 31, 33 on the other comers and these lugs 31, 33 have holes 35 therein through which other fasteners 37 pass. The fasteners 37 cooperate with threaded holes 39 in the base plate 29. In this way, the four interconnected housing units 13, 15, l7, 19 are removably secured to the base plate 29. In the base plate 29, there is a centrally located rectangular (usually square) opening 41 through which a cast strand 43, shown in cross section, passes.

FIG. 2 illustrates the housing unit 19 in vertical crosssection and it is understood that the other three housing units 13, 15, 17 are identical and it is considered unnecessary to describe them hereinafter.

Housing unit 19 comprises three side walls 45, 47, 49; a top 51 and a bottom 53. The top 51 is provided with a recess 55 in which are disposed the top edges of a plurality of spaced-apart guide plates 57. I

The guide plates 57 are substantially rectangular, but each one has a chamfered upper corner 59 as shown on FIG. 2. The guide plates 57 are unitized by being welded, or otherwise securely fastened, to a backing plate 61.

On the outer surface of the backing plate 61 there is mounted an internally threaded cylinder or nut 63 into which is threaded one end of a closed ended tubular or spring housing 65. The closed end of the tubular or spring housing 65 has a hole 67 therethrough and extending through the hole is a bolt shank 69.

The bolt shank 69 is secured to a plunger 71 disposed within the spring housing 65, that coacts with a spring 73, preferably of the Belleville type. The spring 73 coacts with a set screw 75 that is treaded into the open end of the spring housing 65.. The bolt shank is threaded, as shown in FIG. 2, and cooperates with a threaded aperture 77 in the side wall 47.

The bottom 53 is pierced by a plurality of angularly arranged holes 79 in each of which there is a water spray nozzle 81. The holes 79, as shown in FIG. 3, are disposed midway between adjacent spaced apart guide plates. In the embodiment of the invention shown in FIG. 3, a total of three nozzles 81 perhousing unit are installed. Of course, in some applications, more or less number of nozzles 81 may be used if preferred. Thebottom 53 is also pierced by a single drain hole 83 located about where shown in FIG. 3. This hole carries away cooling'water that collects in the housing when the spray nozzles 81 are in service as described hereinafter.

From FIG. 2 it will be noticed that the top 51 and the bottom 53 of the housing units 13, 15, 17, 19 are spaced apartsome distance from the skin of the cast strand 43, but that the guide plates 57 are spaced apart only a very small distance from the skin of the cast strand 43. The distance that the guide plates 57 are spaced apart from the skin of the cast strand 43 is, of course, variable and may be changed by turning the bolt shank 69 by manually or with a suitable tool applied to the hex head portion of the bolt shank.

The side wall 47 is also provided! with a threaded aperture 85 in which is threaded a conduit 87. The conduit 87 is connected to a source of fluid, such as air under pressure, or it may be connected to a vacuum device for removing air from the interior of the housing unit and creating thereby a partial vacuum therein.

Those skilled in the art will appreciate that superatmospheric pressure in each housing unit effects a support for the skin of the cast strand and thereby helps to prevent break outs. A partial vacuum in each or a selected housing unit allows the strand, while yet in the mold cavity to enlarge so that the skin contacts more surface of the mold walls. This allows for greater heat transfer and produce greater thickness of the skin of the strand.

In operation, the cast strand cooling support system of the present invention will be secured to the base or adapter plate 29 which itself is secured to the bottom of a conventional casting mold. The set screw 75 in each tubular cylinder 65 will have been set at a preselected location therein and the bolt shank 69 will have been advanced toward the set screw so as to compress the spring 73.

Then, as soon as the continuous casting process commences and the cast strand emerges from the casting mold, the water sprays emit cooling water onto the skin of the cast strand to effect cooling of it and to thicken it.

Those skilled in the art will appreciate that the vertical face of each guide plate, shown as a straight line in the drawings, may also be curved along an arc of any preselected radius and thereby guide a cast strand that is being curved toward a horizontal attitude. In practice the assembly comprising the guide plates, the backing plate, and the cylindrical member may be removed from each housing and another assembly that includes guide plates having an arcuate face adjacent the cast strand may be installed in each housing unit.

Further, those skilled in the art will understand that the guide plates-may be used as supports for a plurality of rollers, or for only one roller, that guide the cast strand. When a plurality of rollers are used in the manner suggested, they may be so arranged that they follow the surface of path toward a horizontal attitude.

Maintenance of the apparatus of the invention is easily and quickly effected. Upon removing three bolts from any one housing unit (two that are threaded into the base plate, and one in a hinged corner) it may be pivoted about a corner to a position like that shown in FIG. 1. The adjustment bolt 69 allows the interior assembly to be extended out of the housing so that the tubular spring housing 65 can be unscrewed from the nut 63 and the assembly removed.

From the foregoing description of one embodiment of the invention, those skilled in the art should recognize many important features and advantages of it, among which the following are particularly significant:

That the strand guiding devices are enclosed in individual housing units or chambers, and the pressure within these chambers may be varied to produce a desired effect on the skin of the cast strand as it passes through the strand cooling support system;

That each housing unit or chamber is individually removable from the other such units as desired;

That the guide plates within each housing unit or chamber are readily adjustable whenever it is necessary due to wear by the strand rubbing on the face of the guide plates. Adjustment is effected by inserting a rectangular (or square) jig through the mold and then tuming the adjustment screws in each housing unit or chamber;

That in addition to providing guidance of the skin of the cast strand during passage through the apparatus of the invention, each housing unit or chamber is fitted with nozzles so that a cooling agent may be applied to the skin of the cast strand in order to cool and thicken it;

That the cooling agent in each housing unit or chamber provides a suitable seal around the periphery thereof adjacent the cast strand whenever a partial vacuum is impressed on the interior of the chamber. Whenever a positive pressure, above atmospheric pressure, is maintained in each chamber, the cooling agent is free to flow therefrom through the drain hole provided in each chamber;

That each housing unit or chamber is an independent unit. Wherefore, many combinations of strand guidance and rate of cooling are possible. Different pressures and different cooling rates may be established as desired in order to achieve a desired effect or to meet different casting conditions; and

That the'resilient supports for the guide plates permits these plates to give under pressure so that the skin of the cast strand may wander a small amount during casting.

Although the invention has been described herein with a certain degree of particularity it is understood that the present disclosure has been made only as an example and that the scope of the invention is defined by what is hereinafter claimed.

What is claimed is:

1. In a continuous casting apparatus including a mold from which a cast strand is continuously withdrawn, the improvement comprising:

a. a plurality of chambers having one open side that a is disposed opposite a surface of said cast strand,

with each chamber including:

i. a plurality of guide members adjustably mounted therein,

ii. means for adjusting the position of each guide member relative to the surface of said cast strand,

iii. means within said chamber for ejecting coolant medium onto the surface of said cast strand; and

b. means mounting each chamber adjacent said mold.

2. The invention of claim 1 wherein:

a. said chambers are hingedly interconnected.

3. The invention of claim 2 wherein:

a. said chambers are secured to a common baseplate that is mounted to said mold.

4. The invention of claim 1 wherein:

a. said guide members are arranged in spaced apart relation and are a unitized structure; and wherein b. said means for adjusting said guide members includes:

i. a threaded member extending into and outside of said chamber and terminating internally thereof adjacent said guide member, and

ii. resilient means coacting with said threaded member and said unitized structure.

5. The invention of claim 4 wherein:

a. said resilient means is disposed within a closed structure that is threadedly connected to said unitized structure; and wherein b. said chamber is provided with fluid drainage means.

6. The invention of claim 4 including:

a. means for pressurizing the interior of each said chamber.

7. In a continuous casting apparatus including a mold from which a cast strand is continuously withdrawn, the improvement comprising:

a. a plurality of chambers each one having one open side that is disposed toward the surface of said cast strand, with each chamber including:

i. a plurality of spaced apart guide plates adjustably mounted inside said chamber and having one edge surface disposed adjacent said cast strand;

ii. means interconnecting said guide plates as a unitized structure;

iii. an internally threaded member secured to said interconnecting means,

iv. a threaded tubular member coacting with said internally threaded member and containing an adjusting screw that is adapted to coact with said interconnecting means, and a resilient member that coacts with said adjusting screw and with a plunger;

b. a threaded adjusting member fixed to said plunger and extending externally of said chamber with a portion of said adjusting member coacting with a threaded aperture in a wall of said chamber;

c. at least one fluid spray nozzle in each chamber for ejecting a cooling fluid onto the surface of said cast strand;

d. means for pressurizing the interior of each chamher; and

e. fluid drainage means in each chamber.

8. The invention of claim 7 including:

a. means hingedly interconnecting two or more of said chambers.

9. The invention of claim 8 including:

a. means removably securing each chamber to said mold.

10. The invention of claim 8 including:

a. a plate that is connectable to said mold and to which each chamber is removably connected. k t 

1. In a continuous casting apparatus including a mold from which a cast strand is continuously withdrawn, the improvement comprising: a. a plurality of chambers having one open side that is disposed opposite a surface of said cast strand, with each chamber including: i. a plurality of guide members adjustably mounted therein, ii. means for adjusting the position of each guide member relative to the surface of said cast strand, iii. means within said chamber for ejecting coolant medium onto the surface of said cast strand; and b. means mounting each chamber adjacent said mold.
 2. The invention of claim 1 wherein: a. said chambers are hingedly interconnected.
 3. The invention of claim 2 wherein: a. said chambers are secured to a common baseplate that is mounted to said mold.
 4. The invention of claim 1 wherein: a. said guide members are arranged in spaced apart relation and are a unitized structure; and wherein b. said means for adjusting said guide members includes: i. a threaded member extending into and outside of said chamber and terminating internally thereof adjacent said guide member, and ii. resilient means coacting with said threaded member and said unitized structure.
 5. The invention of claim 4 wherein: a. said resilient means is disposed within a closed structure that is threadedly connected to said unitized structure; and wherein b. said chamber is provided with fluid drainage means.
 6. The invention of claim 4 including: a. means for pressurizing the interior of each said chamber.
 7. In a continuous casting apparatus including a mold from which a cast strand is continuously withdrawn, the improvement comprising: a. a plurality of chambers each one having one open side that is disposed toward the surface of said cast strand, with each chamber including: i. a plurality of spaced apart guide plates adjustably mounted inside said chamber and having one edge surface disposed adjacent said cast strand; ii. means interconnecting said guide plates as a unitized structure; iii. an internally threaded member secured to said interconnecting means, iv. a threaded tubular member coacting with said internally threaded member and containing an adjusting screw that is adapted to coact with said interconnecting means, and a resilient member that coacts with said adjusting screw and with a plunger; b. a threaded adjusting member fixed to said plunger and extending externally of said chamber with a portion of said adjusting member coacting with a threaded aperture in a wall of said chamber; c. at least one fluid spray nozzle in each chamber for ejecting a cooling fluid onto the surface of said cast strand; d. means for pressurizing the interior of each chamber; and e. fluid drainage means in each chamber.
 8. The invention of claim 7 including: a. means hingedly interconnecting two or more of said chambers.
 9. The invention of claim 8 including: a. means removably securing each chamber to said mold.
 10. The invention of claim 8 including: a. a plate that is connectable to said mold and to which each chamber is removably connected. 